DCS: Black Shark - Q&A **READ FIRST!**

[amalahama]

I have a question linked with Ka-50 and coaxial rotors.

 

In typical anti par helicopters, when the speed goes up, we can have a blade stall, because the retreating blades have a much lower speed than advanced blades. But Ka-50 has 2 rotors rotating in different directions. So, the blade stall is experienced in an atypical way,it isn't? (I mean, the helicopter doesn't trend to flip) What's happen when the speed limit is reached?

 

Regards!!!

[britgliderpilot]

I have a question linked with Ka-50 and coaxial rotors.

 

In typical anti par helicopters, when the speed goes up, we can have a blade stall, because the retreating blades have a much lower speed than advanced blades. But Ka-50 has 2 rotors rotating in different directions. So, the blade stall is experienced in an atypical way,it isn't? (I mean, the helicopter doesn't trend to flip) What's happen when the speed limit is reached?

 

Regards!!!

 

I'm not sure you ever reach the speed limit for blade stall - you'll run into another problem first.

 

Consider for a moment the problem of the advancing blade rising when you have a coaxial rotor system . . . .

[amalahama]

I'm not sure you ever reach the speed limit for blade stall - you'll run into another problem first.

 

Consider for a moment the problem of the advancing blade rising when you have a coaxial rotor system . . . .

 

mmm let me thinking about it...

 

Maybe when the speed goes up, the bottom advanced blades tend to bend meanwhile the on top retracting blades don't tend to bend so much, so both blades can impact??

 

Regards!!

[EvilBivol-1]

I am going to carry over a question I had in another topic. Is the terrain of BS fit for the future? Would the planned new engine (whatever this includes) make the terrain technology of BS outdated? Would ED want to invest the time in upgrading the current terrain to the new technology, build it again from scratch or go on to a new theater?

New engine is a new engine. Although an upgrade to the product, the technology itself is completely new. No other info yet; no time estimates, either. For all, I understand it may be hard to resist discussing (speculating) and even making wishlists for it and I myself am very much looking forward to more about this, but at this point ED is very hesitant to discuss anything significantly in the future. There's still plenty work left on the first DCS release, let alone the planned follow-up modules and the improvements they may bring to the existing engine, if it will still be in use. I'm sure more information will be released when the team feels more confident in the accuracy of the information they provide. We're all too familiar with the mistake of discussing plans which are subject to change, delay or cancellation.

 

Maybe when the speed goes up, the bottom advanced blades tend to bend meanwhile the on top retracting blades don't tend to bend so much, so both blades can impact??

Exactly. When traveling at high speed, the blades on the right side come very close as the lower blades bend up.

[RvETito]

The coaxial rotors incline toward the retreating blade like any other rotor. The upper rotor rotates clockwise seen from above and the lower rotates counterclockwise. That means that the upper will incline to the right (the blades are retreating from 0 to 180' azimuth) while the lower will incline to the left. As a result the gap between the two rotors decreases in the 2-4 o'clock sector (right hand side) during forward flight. Right pedal input (increase differentialy lower's rotor collective pitch and decreasing upper's collective) further decreases the gap. For that reason all Kamov helicopters there severe limitations of right pedal inputs at high speed both IRL and BS.

[nemises]

which for me begs the question (for me, with no research), what significant advantages does the twin co-ax configuration bring?

 

I understand there is a massive increase in load potencial (like in the Gazelle?) , but the BS isn't a transport helo..

 

Is it the simplification of the anti-torque tail rotor being uneccesary?

Are there some sort of stealth (audio, IR or radar) improvements?

 

It seems uneccesarily risky to put two fragile counter-rotating wings so close together..

 

Still, there must be a good reason, and I'm sure someone here knows it :)

[RvETito]

Ok, where to start... Pick up some popcorn and make yourself confortable because it's gonna be a loooong story :D

 

Coaxial rotor system

 

Advantages:

1. Rotor efficiency coefficient 12% better than a single rotor with the same diameter, blade airfoil and fill ratio (proportion between the total blades' area and rotor disk area) due to greater airflow mass. The upper rotor (UR) twists the flow down and makes it narrow, as a result the UR's downwash intersects lower rotor (LR) disk at 75-80% of the rotor radius. With the outer 20-25% the LR interacts with additional air increasing the total mass of useful airflow. Same as any propeller or jet engine the thrust is in direct ratio to the airflow through the machinery.

2. Lack of tail rotor wich consumes additional 7-8%. In total the coaxial rotor requires 20% less input power to produce the same thrust compared to equivalent single rotor. All the engine output power goes to the main rotors for lift and control, the power for driving accessories is negligible.

3. Independance of controls. In single rotor design when you increase/decrease the collective pitch you change the torque which must be compensated by tail rotor(pedal) input. The coaxial helicopter is actualy easier to fly, it resembles pretty much flying a fixed wing- no cross connections.

4. More compact design. The lack of long tailboom with rotor and trasmission is a useful feature for naval usage, no wonder Kamov are the king on russian vessels. That brings are features as well. The tail rotor/transmission of the single rotor design has proven to be the reason for the majoruty of aircraft losses in combat- long and badly protected driveshaft- not that hard to damage it with any fire. You loose your tail rotor and you're history. The more compact design allows better protection of crucial components- bulletproff devices are shield for more 'soft' stuff. So in terms of combat survivability I think coaxial helos come in front.

5. Better maneuverabilty.

- because of 1. and 2. a coaxial helicopter can climb faster than any other single rotor. If you operate it mountaneus landscape like Caucasus for example you'll certainly appreciate that. During Ka-50's operations in Chechnya it has proven that there are no limits for it because of the terrain- some of the pilots, being ex Mi-24 pilots say that they wouldn't go in some valleys with the Hind while the Ka-50 has given to them great confidence that they can always get away of there simply by pulling on the collective. They say- in single rotor design you naturally look horizontaly for escape route while in this you can go either way.

- ability for sideward and backward flight at speed of about 100km/h. The single rotor helicopter again will be in trouble here, especially in sideward flight, because of tail rotor vortex ring occurance.

There are other issues like maintenance but they are not that comprehensive.

 

Drawbacks:

- risk of blades intersection. Kamov have studied the problem carefully and have found the optimal gap between the rotors to ensure proper operation. If the helicopter is operated within the flight limits there's no problem. However, sometimes, especialy in combat, pilot might need to exceed the aircraft's limitations. There are a couple of crashes for that reason.

- complex construction of the rotor mast assembly. This is also more a maintenance issue because once installed and properly adjusted it's buletproof.

 

I can talk for hours more but I think this should be enough to make the picture. If you have any specific questions don't hesitate to ask ;)

[RvETito]

1. Yes.

 

2. Yes but only about the ADF- the Ka-50 doesn't have a VOR/DME equipment.

[Nordic]

What are the single functions of the autopilot? And is position hold possible?

[diomedes33]

Ok, where to start... Pick up some popcorn and make yourself confortable because it's gonna be a loooong story :D

 

Coaxial rotor system

 

Advantages:

 

Another advantage to add to AirTito's excellent post is safety. Even though tail strikes in any aircraft isn't a good thing, in a conventional helicopter its really bad. Also ground and maintenance crews only have to worry about the two big spinning rotors above their heads and not one that they can walk into.

[RvETito]

What are the single functions of the autopilot? And is position hold possible?

 

It has all the features of the real thing modeled- hover, enroute, descending, attitude stabilization. Try fly with disengaged autopilot- you'll find yourself in a real adventure...:D

[RvETito]

Another advantage to add to AirTito's excellent post is safety. Even though tail strikes in any aircraft isn't a good thing, in a conventional helicopter its really bad. Also ground and maintenance crews only have to worry about the two big spinning rotors above their heads and not one that they can walk into.

 

Well that's true but you must bare in mind the extremely powerful downwash the coaxial rotor produces. I'm a big guy (height 1.92m, weight 92kg) and I have to work hard just to stand on my feet while there's a Ka-32 taking-off or just taxiing near by. I've witnessed how a 50kg mechanic was blown away like a leaf after not paying attention :) Also, anything(including tools) left inside and close to the rotor disk area will eject like a projectile once the downwash reaches it. That's why I always check the area around the helicopter for any kind of foreign objects despite that's it's not written in the manuals.

[quo vadis]

It has all the features of the real thing modeled- hover, enroute, descending, attitude stabilization. Try fly with disengaged autopilot- you'll find yourself in a real adventure...:D

 

attitude stabilization ? Like, preventing the pilot to become too angry ? :music_whistling:

 

Thanks for the movie. I've found another advantage of co-axial rotors: They turn really slowly... And backwards..:lol:

[SimFreak]

Here's a Q I forgot to ask at E for All.

 

Will MBT deploy smoke cover to protect self?

[Nordic]

Thx for info AirTito.

Regarding downwash: are we going to see something like that by firing a missile:

[EvilBivol-1]

Here's a Q I forgot to ask at E for All.

 

Will MBT deploy smoke cover to protect self?

Going from Dmut's answer on the Russian forum, it isn't likely for Back Shark, although certainly something to address as soon as possible. The main difficulty isn't so much the popping of the smoke, but coding all of the AI targeting systems and logic to properly calculate and counteract the effect of smoke masking.

 

Definitely on the list for implementation, but most likely not in the first release.

 

Regarding downwash: are we going to see something like that by firing a missile:

Again, probably not in Black Shark, but maybe after.

[Topo]

At what extent the ground veichle AI react on our attack? (Columns evade from road, serch cover etc..)

and will be improved the radio comms with tower, ground forces ecc..?

Thanks.

 

Saluti.

[Weta43]

It's been said that they fire back W/ MG while still engaging primary target.

[Dmut]

At what extent the ground veichle AI react on our attack? (Columns evade from road, serch cover etc..)

no

Hopefully they'll at least fire back with machineguns...

yes. and if you will hover sometime before tanks - they will fire with main gun.

[Topo]

umh.. Ka-50, AH-64 and A-10 are primary intended for CAS mission; a more reactive ground unit is a must, imho;

it's possible in future versions?

 

Thanks and excuse my poor english :-)

[SuperKungFu]

Here's a simple question: when you run the ka-50 into powerlines, will that cause any damage or will the lines simply break like in lock on with the jets?

[EvilBivol-1]

umh.. Ka-50, AH-64 and A-10 are primary intended for CAS mission; a more reactive ground unit is a must, imho;

it's possible in future versions?

 

Thanks and excuse my poor english :-)

Yes, if not in Black Shark, than likely after. And don't worry about your English. :)

 

Here's a simple question: when you run the ka-50 into powerlines, will that cause any damage or will the lines simply break like in lock on with the jets?

It will cause damage, though I'm not certain as to whether this damage will be scripted to always happen the same way or depend on where you collide exactly. Hard to say at this point as the damage model is not yet complete.

[BBQ]

In single player, will I be able to pilot any other ship than "lead" in a flight?

[AlphaOneSix]

Please tell me that's going to be modelled on the Apache! *Fingers crossed*

 

Only the oldest Hellfire missiles (AGM-114A) smoke like that. They were replaced by the smokeless AGM-114C before the Apache ever even saw combat. All of the newer Hellfires also have smokeless motors as well. So if smoke ever gets modeled, so too must the dismal failure rate of the AGM-114A. ;)

[Malleus]

I agree with that, some kind of reaction against attack is a must have for AI ground. Almost the simplest one " run for cover ".....

 

Indeed, even just starting moving around unpredictably, especially since BS is about engaging ground forces. Fighter/airplane AI is not important at this point, but without decent ground AI, it might just be another castle sank into the swamp, despite being utterly awesome in the simulation department (which alone would be worth the money though).